U.S. Pat. No. 5,522,803, being now as a reference deemed to constitute a part of the present text, shows in FIGS. 1 and 2 a cannula housing to be adhered to the skin of the patient so as to enable continuous administration of a drug to the patient via a plastics needle introduced into the skin of the patient. At its one end a tubing features a coupling that is releasably secured to the cannula housing, whereby the tubing can be released from the cannula housing, eg when the patient is in the bath. At its other end the tubing features a source coupling by which the tubing can be coupled to a source, such as a pump, thereby enabling the drug to be fed to the cannula housing through the tubing.
In some situations, eg when the patient is asleep it is necessary to have a relatively long distance between the cannula housing and the source of the drug to enable the source of drug to sit on a table next to the patient. Thus there is a need for a comparatively long tubing, eg a tubing having a length of about 1.1 m. Conversely, a short tubing is typically desired when the patient is up and about, ie when the source of drug is carried by the patient, eg in a pocket in his clothes. To overcome this problem, it is an option to change tubing as day turns into night. This, however, may lead to waste of the usually very expensive medicament located in the long tubing.
It is previously been attempted to solve this problem by providing the source of drug with a winder mechanism for the tubing, see international patent application No. WO 96/35472. The winder mechanism described therein, however, cannot be manufactured at low costs and there is a risk of the winder mechanism getting stuck.
U.S. Pat. No. 4,406,042 discloses a tubing clips where variation of the distance between the ends of the tubing is by changing the size of a tubing loop that projects from the clips.